With reference to FIG. 1, a conventional food dehydrator is shown to include a housing 9, an air intake pipe 8, and a plurality of food trays 7. The housing 9 includes a rear chamber 91 downstream of the air intake pipe 8, a front chamber 92 downstream of the rear chamber 91, and an outlet port 93 downstream of the front chamber 92. The air intake pipe 8 is disposed to introduce a stream of hot air into the rear chamber 91. The food trays 7 are removably disposed in the front chamber 92. As shown in FIG. 2, each of the food trays 7 has a mesh bottom wall 71 and a surrounding wall 72 extending upwardly from a periphery of the mesh bottom wall 71. The mesh bottom wall 71 and the surrounding wall 72 cooperatively define a dehydration space 73 for dehydration of food. The surrounding wall 72 has an inlet 721 in fluid communication with the rear chamber 91. During dehydration of food, the hot air introduced into the rear chamber 91 flows through the inlets 721 of the food trays 7 into the dehydration spaces 73 of the food trays 7 and then upwardly to pass through the mesh bottom walls 71 of the food trays 7 and leaves the front chamber 92 through the outlet port 93. However, since hot air is introduced into the front chamber 92 through a single air intake pipe 8 and the dehydration spaces 73 of the food trays 7 are in fluid communication with one another, if different food items are dried on the food trays 7 at the same time, the flavors of the food items will mix.